Alternating-current rectifier



F. BLASER. ALTERNATING CURRENT RECTIFIER. APPLICAHON FILED JULY 27.1922.

"1,437,336. Patented Nov. 28,1922.

Fl 1. v 5 e 2 Q fxira/zfar 1'7 B/aser Patented Nov. 28, 1922.

UNITED STATES I FRITZ BLASER, OF AARAU, SWITZERLAND.

ALTERNATING-CURRENT RECTIFIER.

Application filed July 27,

To all whom it may concern Be it known that I, FRITZ BLASER, a citizen of the Republic of Switzerland, residing at Aarau, Canton of Aarau, Republic of Switzerland, have invented certain new and useful Improvements in and Relatin to Alternating-Current Rectifiers, of which the following is a specification.

This invention relates to alternating current rectifiers and has for its main object to provide an apparatus by which an alternating current may be converted into a pulsating continuous current for charging accumulators or the like without sparking and without wasteful discharge of the accumulator during the period when the alternating current wave is near zero.

A further object of the invention is the provision of apparatus of this character in which the discharge current from the accumulators may be utilized to assist in carry- 3 ing an overload of the alternating current circuit.

According to the present invention, a plurality of contact elements and an inductance are connected in series withan accumulator and form, at the moment the alternating current wave is at zero and the contact elements are changed over, a closed circuit through which the flow of discharged current from the accumulator is minimized and opposed by the choking effect of the inductance, the contact elements being electroma etically actuated in response to the reversa s of current in the alternating current circuit.

In the accompanying drawing wherein several approved embodiments of the in vention are illustrated Figure 1 is a diagrammatic view of one form of the rectifier, the contact elements being shown in' their transitory positions.

Figs. 1 and 1 are detail views showing .the alternative positions of the contact elements.

Fi s. 2 and 3 are diagrammatic views of modifications of the rectifier.

Referring to the drawing in detail, and more particularly to Fig. 1, a is a polarized armature which is caused to vibrate by an electromagnet f, one end of the coil of which latter is connected with a conductor 10 forming part of an alternating current circuit 10-11 whereby the spring contact element 0 which supports the armature a, is caused to vibrate in synchronism with the frequency of the alternating current. A

1922. Serial N0. 577,982.

' stationary cont-act element 6 engages on the same side as the oscillating contact element 0 against the double spring contact (I and when at rest, the oscillating contact element 0 rests lightly against the double contact element d.

s and s are accumulators and 9 indicates a branch conductor of the conductor 11 which is connected with the negative pole of the accumulator s and with the positive pole of the accumulator 8 The negative pole of the accumulator s is connected by a conductor 1' with the stationary contact element 7), a choke coil or other inductance 6 being interposed in said conductor. The positive pole of the battery 8 is connected with the armature actuated contact element 0 by a conductor 11 while the other contact element 03 is connected with the alternating current conductor 10.

The two different positions of the contact elements are shown in Figs. 1 and 1 as they occur at the apex of the alternating current waves, Fig. 1 illustrating the position for one wave and Fig. 1 the position for the other wave. The difl'erent sets, of arrows show theflow of current for the two positions of the contact elements, the full arrows showing the direction of current flow with the contact elements in the position illustrated in Fig. 1 during the charging period of the accumulator s and the dotted arrows indicating the direction of current flow with the contact'elements in the position indicated in Fig. 1 during the charging period of the accumulators 8 The operation of the rectifier for charging the accumulators is as follows: The polarity of the armature a is such that an alternating current impulse flowing through the coil of the magnet f in the direction of the full line arrow will charge the core of the electromagnet in such sense as to attract the armature a thereby moving the double contact element d oil of the stationary contact 6 and permitting the current to flow from the conductor 10 through the contact elements d, a, conductor 12., accumulator s and branch conductor g to the conductor 11. The next current impulse in the alternating circuit flows in the opposite direction as indicated by the dotted arrows and, reversing the polarity of the electro-magnet f, repels the armature a, moving the latter to the position indicated in Fig. 1 and interrupting the flow of current through the accumulator s and closing the electrical connection between the stapurpose.

tionary contact element 2) and the double contact element (Z. With-the double contact element in this position, the current flows through the conductor 11 in the direction of the dotted arrow and enters the positive side of the accumulator 3 through the branch conductor 9 and thence into the conductor 10 through the conductor 2', inductance e and contact elements Z) and d.

During the brief period. when the two contact elements 6 and c bothengage the double contact element (Z and whileithe alternating current wave is at ,zero, the accumulator s is connected in series with the inductance e and the other.accumulator .8 through the conductor 2',.inductance 6, contact elements 7), (Z and a, conductor 7t, accumulator s and branch conductor g. Due to the arrangement of the double ,spring contact. clen'ient (Z relative to vthe stationary contact.element b, the time interval of actual contact between the two contact elements Z) and 0 and the double contact element (Zis, however, reduced tosucha negligibly short period, vthat the inductance e eflectively acts toprevent the growth of the accumulatorcurrent to its full value and hence wasteful discharge of the batteries due to, theshort circuit is avoided while at thesame time the tendency of sparking at the contact points is reduced. Furthermore, the inductance e prevents the backiflow of current fromthe accumulator; 8 into the alternating. current circuit when the fluctuating impressed electromotive force/jot .therectified current is less than the counter, electro-motive force of V thataccumula tor; the coil f performing a like function for the accumulator s.

, lYhen it is desired to discharge the current of the accumulators stands into the alter nating current circuit 10 -ll, the conductors ]L and i of the positive and negative poles of the accumulatorsc and s respectively,

may be interchanged, a double throw switch of the type indicated atBO being used torthe tained by reversing the polarization of the armature a. The effect of either one oil the alcovementioned changes is to so connect the accumulators with the alternating current c rcu t that their electromot ve force 18 added to that eithe alternatingcurrent circuit and the I accumulators thus assist 1n carrying such excessive loads as maybe posed on the alternatingcurrent circuit or in instances where the efficiency of the source of the alternating, current falls below normal. VVitht-herectifier apparatus operating in this manner, the accumulators are caused to intermittently discharge into the alternating current circuit in synchronism with the trequencyiot the alternating; current circuit and in proper phase relation to the alternat ng current.

In the modlticatlon oi the invention illustrated in Fig. 2 there is shown an arrangement of two sets o'l contact elements, 7), c and (Z, and 5, ct" and c which are controlled according to the frequency and direction of current flow in the alternating current circuit 101l and operate to supply a unidlrectional current to the accumulator a. in

this arrangement,the conductor ll) is connected with the coil of the electroinagnct and with the double spring contact element d of the lower set of contact elements. The

double spring contact element (Z of the upper 'set of contact elements is connected with the ductance e,which lat teiyis also connected with the'positive pole ol. the accumulator s by aconductor i.

' ln this form of the invention two arinatures a and a are utilized to actuate the ,contact elements 0 and 0, respectively, both @LPIDMZUIGS being polarized in a like sense and arranged adjacent the opposite poles of the electromagnet In operation, an alternating current impulse flowing in the direction of the full line arrow over the alternating current conductor 10 passes through the coil of the, electro magnet f and energizes the latter in such sense as to cause the attraction of the armature a and the repulsion oi the armature a so that cont-act between the contact elements I) and (Z is interrupted andthe current flows from the double contact element cl through .the contact element 0, conductor g, inductance eand' conductor 71 tothe positive pole oi the accumulator s. From the negatiic pole of the accun'iulator s to the conductor Ill. oil the alternating current circuit, the current follows the path indicated at 1 2. (1' and (Z. Upon reversal oi? the direction otthe flow oi current in the alternating circuit, the polarity of the magnet 7 is reversed there- .byattracting the ari'nature a and repelling the armature a. With this change in the positions oi the armatures, the double contactelements (land (Z' engage their respec tive stationary contact elements 6 and b and the alternating current impulse flowing in the direction of the dotted line arrow from the conductors 11 flows through theidouhle contact element (Z, stationary contact element Z), conductor 9 inductance (a, conductor z to the positive pole of the accumulator s and from the negative pole oi": said accumulator through the conductor it, stationary contact element 7), and double con-- tact element (Z to the coil of the electromagnet f and alternating current conductor 10. In this form of the invention, the inductance 6 acts in the same manner as described in connection with the form illustrated in Fig. 1, when the several contact elements pass through the transitory stages illustrated.

Referring to the modification of the invention'illustrated in Fig. 3, two sets of contact elements 71, c and d, and b, c and rl are also used, the double contact elements d, d of the respective sets being connected with the negative and positive poles, respectively of the accumulator 8 through conductors 20 and 21. The armature actuated contact elements of the upper set and the stationary contact element 1) of the lower set are connected in series with an inductance and with one terminal of the coil of the electro-magnet f, the opposite terminal of which latter is connected with the conductor 10 of the alternating current circuit. The stationary contact element 1) of the upper set and the armature actuated contact element 0' of the lower set are both connected through branch conductors 22 with the conductor 11 of the alternating current circuit, an additional inductance 6' being interposed between the contact elements 6 and 0. in the form of the invention illustrated in Figure 2 the two armatures a and a are polarized in the same sense and upon energization of the electromagnet f are simultaneously moved in the same direction, either upward or downwardly. Assuming an alternating current impulse to be flowing in the direction of the full line arrows over the conductor 11, the current passes through the conductor 22 to the armature actuated contact element 0, double contact d and conductor 21 to the positive pole of the accumulator s. From the negative pole to the accumulator, the current flows from the cond nctor 20 through the double contact element (I, armature actuated contact element (1, inductance e and coil of the electro-niagnet f to the conductor 10. Upon reversal of the flow of current in the alternating current circuit, the current traveling in the direction of the dotted line arrow over the conductor 10 energizes the coil of the electromagnet f and causes upward movement of the armatures a and (1' whereby the double contact elements are permitted to engage the,

stationary contact elements I) and 7). Passing through the coil of the magnet f the current is conducted to the stationary contact element 6, double contact element d and conductor 21 to the positive pole of accumulator s and from the negative pole of the latter through the conductor 20, double contact element (l, stationary contact element 7) to the alternating current conductor 11 through the branch conductor 22 and the inductance c. In this form of the invention the inductance c has the same chocking efi'ect on the current during the brief period when the battery circuit is closed, while by the provision of the additional inductance e, the choking effect of the inductance e is balanced or equalized so that both curves of the alternating current wave will have identically the same charging effect on the accumulator s. This figure further suggests the use of a coil 23 connected across the conductors 20 and 21 of the accumulator s for polarizing the armature a in the desired sense.

What I claim is 1. In an apparatus of the character described, a source of direct electromotive force, a circuit including said source, contact elements connected in series in said circuit, an alternating current circuit connected with the first mentioned circuit, one of said contact elements being movable and two other of said contact elements being both arranged on and engageable with the same side of the movable contact element, one of the last mentioned two contact elements bein movable and the other contact element being stationary and normally engaged by the first mentioned movable contact element, and electromagnetically actuated means associated with said contact elements and actuating the latter to change the connections between the alternating circuit and said source of current in accordance with the alternations in the flow of current through said alternating current circuit.

2. In an apparatus of the character described, a source of direct current, a circuit including said source, contact elements and an inductance connected in series in said circuit, an alternating current circuit connected with the first mentioned circuit, one of said contact elements being movable and two other of said contact elements being both arranged on and engageable with the same side of the movable contact element, one of the last mentioned two contact elements being movable and the other being stationary and normally engaged by the first mentioned movable contact element, and electromagnetically actuated means associated with said contact elements and actuating the latter to change the connections between the alternating current circuit and the source of direct current in accordance with the alternations in the flow of current through said alternating current circuit, said means acting to close the direct current circuit at the moment the connections are changed, and said inductance having a choking efi'ect preventing rapid growth of the direct current in the closed direct current circuit.

3. In a current rectifier, a stationarv contact element, a resiliently supported double contact element normally engaging the stationary contact element, and a vibratory armature actuated contact element, engageable With the double contact element on the same side of the latter as said stationary contact, the vibratory contact being adapted, in one position, to disengage the double cont ct element from the stationary contact element, and, in its other position, to move out of contact With the double contact element and permit the latter to engage the stationary contact element, said double contact element being adapted to simultaneously engage both the stationary and Vibrating contact elements When the latter is in an intermediate position.

4. In an apparatus of the character de scribed, an accumulator, a circuit including said accumulator, an inductance in said circuit, a plurality of sets of circuit changing contact elements interposed in said circuit, the contact elements adapted, when incircuit changing position, to close the circuit including said accumulator and inductance, an alternating current circuit connected. With certain of the contact elements of the respective sets, actuating ar- 25 of each set being 20 

